Electrically programmable fuse structures with narrowed width regions configured to enhance current crowding and methods of fabricating thereof

1. A method of fabricating an electrically programmable fuse for an integrated circuit, the method comprising: forming a fuse on a support structure, the fuse comprising a first terminal portion and a second terminal portion interconnected by an elongate fuse element; wherein the first terminal portion has a maximum width greater than a maximum width of the elongate fuse element and wherein the fuse includes a narrowed width region where the first terminal portion and elongate fuse element interface, the narrowed width region extending at least partially into and comprising part of the first terminal portion, and wherein a width of the first terminal portion in the narrowed region is less than the maximum width of the first terminal portion to enhance current crowding therein; and wherein the method further comprises providing a polysilicon support structure, and wherein forming the fuse further comprises providing a blocking mask over a portion of the polysilicon support structure and siliciding exposed polysilicon of the polysilicon support structure to thereby define a silicide fuse having the narrowed width region at the interface of the first terminal portion and the elongate fuse element, thereby patterning the silicide fuse with a planar configuration different than a planar configuration of the polysilicon support structure.

2. The method of claim 1 , wherein forming the fuse further comprises forming the fuse with the narrowed width region comprising a tapered width region, wherein width of the first terminal portion in the narrowed width region tapers from a first width less than or equal to the maximum width of the first terminal portion to a second width substantially equal to the maximum width of the elongate fuse element, and wherein width of the elongate fuse element is one of a constant width equal to the maximum width thereof, or includes a restricted width region where width of the elongate fuse element is less than the maximum width of the elongate fuse element.

3. The method of claim 1 , wherein forming the fuse further comprises forming the fuse with the narrowed width region having a width less than the maximum width of the elongate fuse element, and wherein the narrowed width region at the interface of the first terminal portion and the elongate fuse element also extends partially into and comprises part of the elongate fuse element, and wherein width of the elongate fuse element outside the narrowed width region is one of a constant width equal to the maximum width thereof, or includes a further restricted width region where width of the elongate fuse element is less than the maximum width of the elongate fuse element.

4. The method of claim 1 , wherein forming the fuse further comprises forming the fuse with the narrowed width region at the interface of the first terminal portion and the elongate fuse element comprising two regions of reduced width coupled in series extending into and comprising part of the first terminal portion, wherein at least one region of the two regions of reduced width is a tapered width region where width of the first terminal portion tapers from a first width less than or equal to the maximum width of the first terminal portion to a second width less than the first width, and wherein width of the elongate fuse element is one of a constant width equal to the maximum width thereof, or includes a restricted width region where width of the elongate fuse element is less than the maximum width of the elongate fuse element.

5. A method of fabricating an electrically programmable fuse for an integrated circuit, the method comprising: forming a fuse on a support structure, the fuse comprising a first terminal portion and a second terminal portion interconnected by an elongate fuse element; wherein the elongate fuse element has a maximum width and includes a restricted width region wherein width of the elongate fuse element within the restricted width region is less than the maximum width of the elongate fuse element to enhance current crowding therein, and a length of the restricted width region is less than a total length of the elongate fuse element; and wherein the method further comprises providing a polysilicon support structure, and wherein forming the fuse further comprises providing a blocking mask over a portion of the polysilicon support structure and siliciding exposed polysilicon of the polysilicon support structure to thereby define a silicide fuse having the restricted width region in the elongate fuse element, thereby patterning the silicide fuse with a planar configuration different than a planar configuration of the underlying polysilicon support structure, and wherein the first terminal portion, elongate fuse element and second terminal portion are coplanar and have a common thickness.

6. The method of claim 5 , wherein forming the fuse further comprises forming the restricted width region in the elongate fuse element intermediate the first terminal portion and the second terminal portion, and wherein the restricted width region is configured to enhance electromigration within the elongate fuse element with establishing of current through the elongate fuse element between the first and second terminal portions.